RFC 1431 (rfc1431) - Page 2 of 19
DUA Metrics (OSI-DS 33 (v2))
Alternative Format: Original Text Document
RFC 1431 DUA Metrics February 1993
8. Strategy for locating entries........................... 9
9. Displaying results...................................... 10
10. Association Handling.................................... 11
11. Suitability for management.............................. 12
12. Query Resolution........................................ 13
13. International Languages................................. 16
14. User Friendliness....................................... 16
15. Operational Use......................................... 17
16. Security Considerations................................. 19
17. Author's Address........................................ 19
1. Overview
The purpose of this document is to define some metrics by which DUA
products can be measured. It should be first be noted that the use
of the term "DUA" is rather misleading. There is an assumption here
that the DUA is implemented correctly and is able to "talk" valid
X.500 protocol: this is a sine qua non. Instead, this document seeks
to draw out the characteristics of Directory user interfaces.
However, the term DUA is persisted with as it is used by most people
when referring to Directory user interfaces. The format of these DUA
metrics is essentially a questionnaire which extracts a detailed
description of a user interface. DUAs come in very different forms.
Many make use of windowing environments, offering a "high-tech" view
of the Directory, while others are designed to work in a terminal
environment. Some interfaces offer extensive control over the
Directory, and thus may be well-suited to Directory managers, while
others are aimed more at the novice user. Some interfaces are
configurable to allow searches for any attribute in any part of the
DIT, while others lack this generality but are focussed on handling
the most typical queries well. In many aspects, it is almost
impossible to say that one DUA is better than other from looking at
the responses to question in this document. A flexible management
tool will be better for management than a DUA aimed at servicing
simple look-ups, and vice-versa. Furthermore, in other areas, there
are several radically different approaches to a problem, but it is
not as yet clear whether one approach is better than another. One
example of this is the extent to which a DUA provides an abstraction
of the underlying DIT hierarchy, either emphasising the world as a
tree or trying to conceal this from the user.
However, other aspects, such as whether the DUA can actually find the
entries required, and if so, how quickly, can be directly measured in
some way. Throughout this document, some of the questions posed are
annotated with a square-bracketed points score and an explanation as
to how the points should be allocated. For example, a question might
be appended with "[2 if yes]", indicating score 2 points for an
affirmative answer to that question. These points scores should be
Barker